Steerable multi-linked  device having multiple working ports

ABSTRACT

A steerable multi-linked device. The device includes a first multi-linked mechanism and a second multi-linked mechanism. The first mechanism defines a first plurality of grooves. The second mechanism defines a second plurality of grooves. The first and second pluralities of grooves cooperate to define at least two working ports along a length of the device. At least one of the first and second mechanisms are steerable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and is a continuation of U.S.patent application Ser. No. 13/469,797, filed on May 11, 2012, which isa continuation of U.S. patent application Ser. No. 11/838,519, filed onAug. 14, 2007, now U.S. Pat. No. 8,192,422, which claims priority toU.S. Provisional Application No. 60/822,280, filed on Aug. 14, 2006, andU.S. Provisional Application No. 60/862,636, filed on Oct. 24, 2006, thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND

This application discloses an invention that is related, generally andin various embodiments, to a steerable multi-linked device havingmultiple working ports.

There are many types of steerable multi-linked devices, and such devicesare utilized in a number of applications. For some of the applications,it is desirable to be able to pass a plurality of devices (e.g., acamera, a fiber optic, a surgical tool, etc.) from a first end of asteerable multi-linked device to a second end of the steerablemulti-linked device. Although some steerable multi-linked devices definea center passage which extends from one end of the device to the otherend of the device, such center passages are generally configured toallow only one device to pass therethrough.

SUMMARY

In one general respect, this application discloses a steerablemulti-linked device. According to various embodiments, the deviceincludes a first multi-linked mechanism and a second multi-linkedmechanism. The first multi-linked mechanism defines a first plurality ofgrooves. The second multi-linked mechanism defines a second plurality ofgrooves. The first and second pluralities of grooves cooperate to defineat least two working ports along a length of the device. At least one ofthe first and second mechanisms are steerable.

DESCRIPTION OF DRAWINGS

Various embodiments of the invention are described herein by way ofexample in conjunction with the following figures.

FIGS. 1A and 1B illustrate various embodiments of a steerablemulti-linked device;

FIG. 2 illustrates various embodiments of a first mechanism of thedevice of FIG. 1;

FIGS. 3A-3C illustrate various embodiments of a first link of the firstmechanism of FIG. 2;

FIGS. 4A-4C illustrate various embodiments of an intermediate link ofthe first mechanism of FIG. 2;

FIGS. 5A-5C illustrate various embodiments of a second link of the firstmechanism of FIG. 2;

FIG. 6 illustrates various embodiments of a second mechanism of thedevice of FIG. 1;

FIGS. 7A-7C illustrate various embodiments of a first link of the secondmechanism of FIG. 6;

FIGS. 8A-8C illustrate various embodiments of an intermediate link ofthe second mechanism of FIG. 6;

FIGS. 9A-9D illustrate various embodiments of a second link of thesecond mechanism of FIG. 6;

FIG. 10 illustrates various embodiments of a motion sequence of thedevice of FIG. 1; and

FIG. 11 illustrates various embodiments of a steerable multi-linkeddevice traversing a path having tight curvatures.

DETAILED DESCRIPTION

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to focus on elementsthat are relevant for a clear understanding of the invention, whileeliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not necessarily facilitate a better understanding ofthe invention, a description of such elements is not provided herein.

FIGS. 1A and 1B illustrate various embodiments of a steerablemulti-linked device 10. As used herein, the term “steerable” means thatan end of the device 10 can be guided in a number of directions (e.g.,up, down, left, right, etc.) relative to another portion of the device10. Various embodiments of the device 10 may be utilized for medicalprocedures (e.g., minimally invasive procedures), for surveillanceapplications, for inspection applications, for search and rescueapplications, etc. For purposes of clarity only, the utility of thedevice 10 will be described hereinbelow in the context of itsapplicability to medical procedures. However, a person skilled in theart will appreciate that the device 10 can be utilized in a variety ofdifferent applications.

The device 10 comprises a first mechanism 12 and a second mechanism 14.According to various embodiments, the second mechanism 14 is structuredand arranged to receive and surround the first mechanism 12 as shown inFIG. 1B. For such embodiments, the first mechanism 12 may be consideredthe inner mechanism or the core mechanism, and the second mechanism 14may be considered the outer mechanism or the sleeve mechanism. Accordingto other embodiments, the first and second mechanisms 12, 14 may bestructured and arranged to have a relationship other than a concentricrelationship. For example, one skilled in the art will appreciate that,according to various embodiments, the first and second mechanisms 12, 14may be structured and arranged to operate in a side-by-side arrangement,where the first mechanism 12 operates adjacent to the second mechanism14. As described in more detail hereinbelow, the first mechanism 12 mayoperate in either a rigid mode or a limp mode, the second mechanism 14may operate in either a rigid mode or a limp mode, and the first andsecond mechanisms 12, 14 may operate independent of one another.

As used herein, the term “limp” means highly flexible. Thus, when eitherthe first or second mechanism 12, 14 is in the limp mode, the limpmechanism either assumes the shape of its surroundings or can bereshaped. It should be noted that the term “limp” as used herein doesnot denote a structure that passively assumes a particular configurationdependent upon gravity and the shape of its environment. Rather, wheneither the first or second mechanism 12, 14 is in the limp mode, thelimp mechanism is capable of assuming positions and configurations thatare desired by an operator of the device 10, and are thereforearticulated and controlled rather than flaccid and passive.

Both the first mechanism 12 and the second mechanism 14 may be steerablemechanisms. Accordingly, it will be appreciated that the device 10 maybe utilized to navigate a luminal space as well as any three-dimensionalpath within an intracavity space. The device 10 may also comprise afirst cable 16, a second cable 18, a third cable 20, and a fourth cable22. The first, second and third cables 16, 18, 20 may be consideredsteering cables, and the fourth cable 22 may be considered a tensioningcable.

FIG. 2 illustrates various embodiments of the first mechanism 12 of thedevice 10. The first mechanism 12 is a multi-linked mechanism andincludes a first end 24 and a second end 26. The first end 24 may beconsidered the proximal end and the second end 26 may be considered thedistal end. The first mechanism 12 comprises a first link 28, a secondlink 30, and any number of intermediate links 32 between the first andsecond links 28, 30. The first link 28 may be considered the proximallink, and the second link 30 may be considered the distal link.

FIGS. 3A-3C illustrate various embodiments of the first link 28 (innerproximal link) of the first mechanism 12. The first link 28 includes afirst end 34 and a second end 36, and defines a longitudinal axis 38that passes through the center of the first end 34 and the center of thesecond end 36 as shown in FIG. 3B. The first link 28 may be fabricatedfrom any suitable material. According to various embodiments, the firstlink 28 is fabricated from a fiber reinforced material such as, forexample, G10/FR4 Garolite®. The first link 28 has a generallycylindrical shaped exterior and is described in more detail hereinbelow.

The first link 28 comprises a first portion 40 and a second portion 42.The first portion 40 may be considered the proximal portion and thesecond portion 42 may be considered the distal portion. The firstportion 40 may be fabricated integral with the second portion 42. Thefirst portion 40 has a cylindrical shaped exterior, and extends from thefirst end 34 of the first link 28 toward the second end 36 of the firstlink 28. According to various embodiments, the diameter of the firstportion 40 is on the order of approximately 6.35 millimeters.

The second portion 42 has a generally cylindrically shaped exterior. Thesecond portion 42 has a cylindrically shaped exterior where it contactsthe first portion 40, and tapers toward the second end 36 of the firstlink 28. The second portion 42 may be shaped in the form of a generallysegmented hemisphere at the second end 36 of the first link 28.According to various embodiments, the diameter of the second portion 42is on the order of approximately 4.75 millimeters where it contacts thefirst portion 40.

The second portion 42 comprises a first surface 44. The first surface 44may be considered the outer surface of the second portion 42. The secondportion 42 defines a first groove 46 parallel to the longitudinal axis38 along the first surface 44, a second groove 48 parallel to thelongitudinal axis 38 along the first surface 44, and a third groove 50parallel to the longitudinal axis 38 along the first surface 44. Each ofthe first, second and third grooves 46, 48, 50 extend along the firstsurface 44 toward the second end 36 of the first link 28. The first,second and third grooves 46, 48, 50 may be semi-tubular shaped and maybe evenly spaced about the first surface 44 of the second portion 42 ofthe first link 28 as shown in FIG. 3C. According to various embodiments,the first, second, and third grooves 46, 48, 50 may be configured in theshape of a segmented cylinder. The size of each of the grooves 46, 48,50 may identical to one another or may be different from one another.For example, according to various embodiments, the first and secondgrooves 46, 48 are configured as segments of a cylinder having adiameter on the order of approximately 1.25 millimeters, and the thirdgroove 50 is configured as a segment of a cylinder having a diameter onthe order of approximately 2.50 millimeters. The length of the firstlink 28 may be on the order of approximately 65 millimeters. However,one skilled in the art will appreciate that the length of the first link28 can vary based on the application.

The first link 28 also defines a passage 52 extending from the first end34 to the second end 36 along the longitudinal axis 38 as shown in FIG.3B. The passage 52 is of a size sufficient to allow the fourth cable 22to pass therethrough. According to various embodiments, the passage 52is generally configured as a complex shape that comprises a combinationof a first cylinder 54 that extends from the first end 34 toward thesecond end 36, and a second cylinder 56 that extends from the firstcylinder 54 toward the second end 36. The diameter of the first cylinder54 is larger than the diameter of the second cylinder 56. For example,according to various embodiments, the first cylinder 54 has a diameteron the order of approximately 3.20 millimeters and the second cylinder56 has a diameter on the order of approximately 1.50 millimeters.

FIGS. 4A-4C illustrate various embodiments of one of the intermediatelinks 32 (inner intermediate link) of the first mechanism 12. Theintermediate link 32 is representative of the other intermediate links32. The intermediate link 32 includes a first end 58 and a second end60, and defines a longitudinal axis 62 that passes through the center ofthe first end 58 and, the center of the second end 60 as shown in FIG.4B. The intermediate link 32 may be fabricated from any suitablematerial. According to various embodiments, the intermediate link 32 isfabricated from a fiber reinforced material such as, for example,G10/FR4 Garolite®. The intermediate link 32 has a generallybullet-shaped exterior and is described in more detail hereinbelow.

The intermediate link 32 comprises a first portion 64 and a secondportion 66. The first portion 64 may be considered the proximal portionand the second portion 66 may be considered the distal portion. Thefirst portion 64 may be fabricated integral with the second portion 66.The first portion 64 has a generally cylindrical shaped exterior, andextends from the first end 58 of the intermediate link 32 toward thesecond end 60 of the intermediate link 32. According to variousembodiments, the second portion 66 has a generally cylindrically shapedexterior where it contacts the first portion 64, and tapers toward thesecond end 60 of the intermediate link 32. The exterior of the secondportion 66 is configured in the form of a generally segmentedhemisphere. According to various embodiments, the diameter of theintermediate link 32 is on the order of approximately 4.75 millimetersat the first end 58 thereof. The length of the intermediate link 32 maybe on the order of approximately 5.85 millimeters. However, one skilledin the art will appreciate that the length of the intermediate link 32can vary based on the application.

The intermediate link 32 also comprises a first surface 68 that extendsfrom the first end 58 of the intermediate link 32 to the second end 60of the intermediate link 32. The first surface 68 may be considered theouter surface of the intermediate link 32. The intermediate link 32 alsodefines a first groove 70 parallel to the longitudinal axis 62 along thefirst surface 68, a second groove 72 parallel to the longitudinal axis62 along the first surface 68, and a third groove 74 parallel to thelongitudinal axis 62 along the first surface 68. Each of the first,second and third grooves 70, 72, 74 extend along the first surface 68from the first end 58 of the intermediate link 32 toward the second end60 of the intermediate link 32. The first, second and third grooves 70,72, 74 may be semi-tubular shaped and may be evenly spaced about thefirst surface 68 of the intermediate link 32 as shown in FIG. 4C.According to various embodiments, the first, second, and third grooves70, 72, 74 may be configured in the shape of a segmented cylinder. Thesize of each of the grooves 70, 72, 74 may identical to one another ormay be different from one another. For example, according to variousembodiments, the first and second grooves 70, 72 are configured assegments of a cylinder having a diameter on the order of approximately1.75 millimeters at the first end 58 of the intermediate link 32, andthe third groove 74 is configured as a segment of a cylinder having adiameter on the order of approximately 2.50 millimeters at the first end58 of the intermediate link 32. The first, second and third grooves 70,72, 74 are each configured to receive and partially surround any of avariety of tools or instruments (e.g., ablation tools) which may passfrom the first end 24 of the multi-linked device 10 to the second end 26of the multi-linked device 10.

The intermediate link 32 also defines a passage 76 extending from thefirst end 58 to the second end 60 along the longitudinal axis 62 asshown in FIG. 4B. The passage 76 is of a size sufficient to allow thefourth cable 22 to pass therethrough. According to various embodiments,the passage 76 is generally configured as a complex shape that comprisesa combination of a first segmented hemisphere 78 that extends from thefirst end 58 toward the second end 60, a second segmented hemisphere 80that extends from the first segmented hemisphere 78 toward the secondend 60, a cylinder 82 that extends from the second segmented hemisphere80 toward the second end 60, and a third segmented hemisphere 84 thatextends from the cylinder 82 to the second end 60 of the intermediatelink 32. According to various embodiments, the first segmentedhemisphere 78 represents a portion of a sphere having a diameter on theorder of approximately 4.75 millimeters, the second segmented hemisphere80 represents a portion of a sphere having a diameter on the order ofapproximately 2.25 millimeters, the cylinder 82 has a diameter on theorder of approximately 1.0 millimeter, and the third segmentedhemisphere 84 represents a portion of a sphere having a diameter on theorder of approximately 2.25 millimeters.

The first segmented hemisphere 78 of the passage 76 is configured toreceive the second end 36 of the first link 28 when the first link 28 iscoupled to the intermediate link 32. Similarly, for a given intermediatelink 32, the first segmented hemisphere 78 of the passage 76 isconfigured to receive the second end 60 of another intermediate link 32when the other intermediate link 32 is coupled to the given intermediatelink 32. The third segmented hemisphere 84 may serve to reduce thepinching or binding of the fourth cable 22 when one intermediate link 32moves relative to an adjacent intermediate link 32 coupled thereto.Similarly, when the second link 30 is coupled to a given intermediatelink 32, the third segmented hemisphere 84 may serve to reduce thepinching or binding of the fourth cable 22 when the second link 30 movesrelative to the given intermediate link 32.

With the above described structure, the first link 28 may be coupled tothe intermediate link 32 by seating the second end 36 of the first link28 in the first segmented hemisphere 78 of the passage 76 of theintermediate link 32. As the convex configuration of the second end 36of the first link 28 generally corresponds with the concaveconfiguration of the first segmented hemisphere 78 of the passage 76 ofthe intermediate link 32, the first link 28 may be coupled to theintermediate link 32 such that the longitudinal axis 38 and the first,second and third grooves 46, 48, 50 of the first link 28 arerespectively aligned with the longitudinal axis 62 and the first, secondand third grooves 70, 72, 74 of the intermediate link 32. Theintermediate link 32 may be moved relative to the first link 28 suchthat the longitudinal axis 62 of the intermediate link 32 is not alignedwith the longitudinal axis 38 of the first link 28. According to variousembodiments, the configuration of the first link 28 and the intermediatelink 32 allows for the intermediate link 32 to be moved relative to thefirst link 28 coupled thereto such that the longitudinal axis 38 of thefirst link 28 and the longitudinal axis 62 of the intermediate link 32are up to approximately 25° out of alignment with one another.Similarly, one intermediate link 32 may be coupled to anotherintermediate link 32, and so on, by seating the second end 60 of oneintermediate link 32 in the first segmented hemisphere 78 of the passage76 of another intermediate link 32. As the convex configuration of thesecond end 60 of the intermediate link 32 generally corresponds with theconcave configuration of the first segmented hemisphere 78 of thepassage 76 of the intermediate link 32, the intermediate links 32 may becoupled such that the respective longitudinal axes 62 and the respectivefirst, second and third grooves 46, 48, 50 of the intermediate links 32are aligned. The coupled intermediate links 32 may be moved relative toone another such that the respective longitudinal axes 62 of the coupledintermediate links 32 are not aligned. According to various embodiments,the configuration of the coupled intermediate links 32 allows for oneintermediate link 32 to be moved relative to an adjacent intermediatelink 32 coupled thereto such that the respective longitudinal axes 62are up to approximately 25° out of alignment with one another.

FIGS. 5A-5C illustrate various embodiments of the second link 30 (innerdistal link) of the first mechanism 12. The second link 30 includes afirst end 86 and a second end 88, and defines a longitudinal axis 90that passes through the center of the first end 86 and the center of thesecond end 88 as shown in FIG. 5B. The second link 30 may be fabricatedfrom any suitable material. According to various embodiments, the secondlink 30 is fabricated from a thermoplastic material such as, forexample, Delrin®.

The second link 30 comprises a first portion 92 and a second portion 94.The first portion 92 may be considered the proximal portion and thesecond portion 94 may be considered the distal portion. The firstportion 92 may be fabricated integral with the second portion 94. Thefirst portion 92 has a generally cylindrical shaped exterior, andextends from the first end 86 of the second link 30 toward the secondend 88 of the second link 30. According to various embodiments, thesecond portion 94 has a generally cylindrically shaped exterior where itcontacts the first portion 92, and tapers toward the second end 88 ofthe second link 30. The exterior of the second portion 64 is configuredin the form of a generally segmented cone. According to variousembodiments, the diameter of the second link 30 is on the order ofapproximately 4.75 millimeters at the first end 86 thereof, and thetaper of the second portion 94 is at an angle of approximately 30°relative to the exterior of the first portion 92. The length of thesecond link 30 may be on the order of approximately 5.90 millimeters.However, one skilled in the art will appreciate that the length of thesecond link 30 can vary based on the application.

The second link 30 also comprises a first surface 96 that extends fromthe first end 86 of the second link 30 to the second end 88 of thesecond link 30. The first surface 96 may be considered the outer surfaceof the second link 30. The second link 30 also defines a first groove 98parallel to the longitudinal axis 90 along the first surface 96, asecond groove 100 parallel to the longitudinal axis 90 along the firstsurface 96, and a third groove 102 parallel to the longitudinal axis 90along the first surface 96. Each of the first, second and third grooves98, 100, 102 extend along the first surface 96 from the first end 86 ofthe second link 30 toward the second end 88 of the second link 30. Thefirst, second and third grooves 98, 100, 102 may be semi-tubular shapedand may be evenly spaced about the first surface 96 of the second link30 as shown in FIG. 5C. According to various embodiments, the first,second, and third grooves 98, 100, 102 may be configured in the shape ofa segmented cylinder. The size of each of the grooves 98, 100, 102 mayidentical to one another or may be different from one another. Forexample, according to various embodiments, the first and second grooves98, 100 are configured as segments of a cylinder having a diameter onthe order of approximately 1.25 millimeters at the first end 86 of thesecond link 30, and the third groove 102 is configured as a segment of acylinder having a diameter on the order of approximately 2.50millimeters at the first end 86 of the second link 30. The first, secondand third grooves 98, 100, 102 are each configured to receive andpartially surround any of a variety of tools or instruments (e.g.,ablation tools) which may pass from the first end 24 of the multi-linkeddevice 10 to the second end 26 of the multi-linked device 10.

The second link 30 also defines a passage 104 extending from the firstend 86 to the second end 88 along the longitudinal axis 90 as shown inFIG. 5B. The passage 104 is of a size sufficient to allow the fourthcable 22 to pass therethrough. According to various embodiments, thepassage 104 is generally configured as a complex shape that comprises acombination of a first segmented hemisphere 106 that extends from thefirst end 86 toward the second end 88, a second segmented hemisphere 108that extends from the first segmented hemisphere 106 toward the secondend 88, and a cylinder 110 that extends from the second segmentedhemisphere 108 to the second end 88 of the second link 30. According tovarious embodiments, the first segmented hemisphere 106 represents aportion of a sphere having a diameter on the order of approximately 4.75millimeters, the second segmented hemisphere 108 represents a portion ofa sphere having a diameter on the order of approximately 2.50millimeters, and the cylinder 110 has a diameter on the order ofapproximately 1.0 millimeter. The first segmented hemisphere 106 of thepassage 104 is configured to receive the second end 60 of anintermediate link 32 when the intermediate link 32 is coupled to thesecond link 30.

With the above described structure, an intermediate link 32 may becoupled to the second link 30 by seating the second end 60 of theintermediate link 32 in the first segmented hemisphere 106 of thepassage 104 of the second link 30. As the convex configuration of thesecond end 60 of the intermediate link 32 generally corresponds with theconcave configuration of the first segmented hemisphere 106 of thepassage 104 of the second link 30, the intermediate link 32 may becoupled to the second link 30 such that the longitudinal axis 62 and thefirst, second and third grooves 70, 72, 74 of the intermediate link 32are respectively aligned with the longitudinal axis 90 and the first,second and third grooves 98, 100, 102 of the second link 30. The secondlink 30 may be moved relative to the intermediate link 32 coupledthereto such that the respective longitudinal axes 62, 90 are notaligned. According to various embodiments, the configuration of thesecond link 30 allows for an intermediate link 32 coupled thereto to bemoved relative to the second link 30 such that the respectivelongitudinal axes 62, 90 are up to approximately 25° out of alignmentwith one another.

FIG. 6 illustrates various embodiments of the second mechanism 14 of thedevice 10. The second mechanism 14 is a multi-linked mechanism andincludes a first end 120 and a second end 122. The first end 120 may beconsidered the proximal end and the second end 122 may be considered thedistal end. The second mechanism 14 comprises a first link 124, a secondlink 126, and any number of intermediate links 128 between the first andsecond links 124, 126. The first link 124 may be considered the proximallink, and the second link 126 may be considered the distal link.

FIGS. 7A-7C illustrate various embodiments of the first link 124 (outerproximal link) of the second mechanism 14. The first link 124 includes afirst end 130 and a second end 132, and defines a longitudinal axis 134that passes through the center of the first end 130 and the center ofthe second end 132 as shown in FIG. 7B. The first link 124 may befabricated from any suitable material. According to various embodiments,the first link 124 is fabricated from a stainless steel material suchas, for example, 316 stainless steel. The first link 124 has a generallybullet-shaped exterior and is described in more detail hereinbelow.

The first link 124 comprises a first portion 136 and a second portion138. The first portion 136 may be considered the proximal portion andthe second portion 138 may be considered the distal portion. The firstportion 136 may be fabricated integral with the second portion 138. Thefirst portion 136 has a cylindrical shaped exterior, and extends fromthe first end 130 of the first link 124 toward the second end 132 of thefirst link 124. According to various embodiments, the diameter of thefirst portion 136 is on the order of approximately 12.70 millimeters.

The second portion 138 has a generally cylindrically shaped exterior.The second portion 138 has a cylindrically shaped exterior where itcontacts the first portion 136, and tapers toward the second end 132 ofthe first link 124. The second portion 138 may be shaped in the form ofa generally segmented hemisphere at the second end 132 of the first link124. According to various embodiments, the diameter of the secondportion 138 is on the order of approximately 9.50 millimeters where itcontacts the first portion 136.

The second portion 138 comprises a first surface 140. The first surface140 may be considered the outer surface of the second portion 138. Thesecond portion 138 defines a first groove 142 along the first surface140, a second groove 144 along the first surface 140, and a third groove146 along the first surface 140. Each of the first, second and thirdgrooves 142, 144, 146 are oblique relative to the longitudinal axis 134and extend along the first surface 140 toward the second end 132 of thefirst link 124. According to various embodiments, each of the grooves142, 144, 146 are oriented at an angle on the order of approximately 15°relative to the longitudinal axis 134. As shown in FIG. 7C, the first,second and third grooves 142, 144, 146 may be evenly spaced about thefirst surface 140 of the first link 124. According to variousembodiments, the first, second, and third grooves 142, 144, 146 may beconfigured in the shape of a segmented cylinder. The size of each of thegrooves 142, 144, 146 may identical to one another or may be differentfrom one another. For example, according to various embodiments, each ofthe grooves 142, 144, 146 are configured as segments of respectivecylinders having diameters on the order of approximately 3.0millimeters. The first, second and third grooves 142, 144, 146 are eachconfigured to facilitate the introduction various tools or instruments(e.g., ablation tools) into the multi-linked device 10. The length ofthe first link 124 may be on the order of approximately 18.5millimeters. However, one skilled in the art will appreciate that thelength of the first link 124 can vary based on the application.

The first link 124 also defines a passage 148 extending from the firstend 130 to the second end 132 along the longitudinal axis 134 as shownin FIG. 7B. The passage 148 is of a size sufficient to allow the firstmechanism 12 to pass therethrough. According to various embodiments, thepassage 148 is generally configured as a complex shape that comprises acombination of a segmented cone 150 that extends from the first end 130toward the second end 132, and a cylinder 152 that extends from thesegmented cone 150 to the second end 132 of the first link 124.According to various embodiments, the segmented cone 150 has a diameteron the order of approximately 7.0 millimeters at the first end 130 ofthe first link 124, and is tapered at an angle on the order ofapproximately 45° relative to the longitudinal axis 134. The cylinder152 has a diameter on the order of approximately 5.50 millimeters.

The first link 124 also defines a first through-hole 154, a secondthrough-hole 156, and a third through-hole 158. (See FIG. 7C). The firstthrough-hole 154 is substantially parallel to the longitudinal axis 134,extends from the first portion 136 toward the second end 132, and ispositioned between the passage 148 and the first surface 140. The secondthrough-hole 156 is substantially parallel to the longitudinal axis 134,extends from the first portion 136 to the second end 132, and ispositioned between the passage 148 and the first surface 140. The thirdthrough-hole 158 is substantially parallel to the longitudinal axis 134,extends from the first portion 136 to the second end 132, and ispositioned between the passage 148 and the first surface 140. The first,second and third through-holes 154, 156, 158 are generally cylindricallyshaped. According to various embodiments, the through-holes 154, 156,158 are evenly spaced from one another as shown in FIG. 7C. The size ofeach of the through-holes 154, 156, 158 may be identical to one anotheror may be different from one another. For example, according to variousembodiments, the respective diameters associated with the through-holes154, 156, 158 may each be on the order of approximately 1.20millimeters. The first through-hole 154 is configured to receive andsurround the first cable 16. The second through-hole 156 is configuredto receive and surround the second cable 18. The third through-hole 158is configured to receive and surround the third cable 20. The first,second and third through-holes 154, 156, 158 may serve as guidepaths formovement of the first, second and third cables 16, 18, 20.

FIGS. 8A-8C illustrate various embodiments of one of the intermediatelinks 128 (outer intermediate link) of the second mechanism 14. Theintermediate link 128 is representative of the other intermediate links128. The intermediate link 128 includes a first end 160 and a second end162, and defines a longitudinal axis 164 that passes through the centerof the first end 160 and the center of the second end 162 as shown inFIG. 8B. The intermediate link 128 may be fabricated from any suitablematerial. According to various embodiments, the intermediate link 128 isfabricated from a polymer thermosplastic material such as, for example,polysulfone. The intermediate link 128 has a generally bullet-shapedexterior and is described in more detail hereinbelow.

The intermediate link 128 comprises a first portion 166 and a secondportion 168. The first portion 166 may be considered the proximalportion and the second portion 168 may be considered the distal portion.The first portion 166 may be fabricated integral with the second portion168. The first portion 166 has a generally cylindrical shaped exterior,and extends from the first end 160 of the intermediate link 128 towardthe second end 162 of the intermediate link 128. According to variousembodiments, the second portion 168 has a generally cylindrically shapedexterior where it contacts the first portion 166, and tapers toward thesecond end 162 of the intermediate link 128. The exterior of the secondportion 168 is configured in the form of a generally segmentedhemisphere. According to various embodiments, the diameter of theintermediate link 128 is on the order of approximately 9.65 millimetersat the first end 160 thereof. The length of the intermediate link 128may be on the order of approximately 8.40 millimeters. However, oneskilled in the art will appreciate that the length of the intermediatelink 128 can vary based on the application.

The intermediate link 128 also comprises a first surface 170 thatextends from the first end 160 of the intermediate link 128 to thesecond end 162 of the intermediate link 128, and a second surface 170that extends from the first end 160 of the intermediate link 128 to thesecond end 162 of the intermediate link 128. The first surface 170 maybe considered the outer surface of the intermediate link 128, and thesecond surface 172 may be considered the inner surface of theintermediate link 128. The intermediate link 32 also defines a firstgroove 174 substantially parallel to the longitudinal axis 164 along thesecond surface 172, a second groove 176 substantially parallel to thelongitudinal axis 164 along the second surface 172, and a third groove178 substantially parallel to the longitudinal axis 164 along the secondsurface 172. Each of the first, second and third grooves 174, 176, 178extend along the second surface 172 toward the second end 162 of theintermediate link 128. The first, second and third grooves 174, 176, 178may be semi-tubular shaped and may be evenly spaced about the secondsurface 172 of the intermediate link 128 as shown in FIG. 8C. Accordingto various embodiments, the first, second, and third grooves 174, 176,178 may be configured in the shape of a segmented cylinder. The size ofeach of the grooves 174, 176, 178 may identical to one another or may bedifferent from one another. For example, according to variousembodiments, the first and second grooves 174, 176 are configured assegments of cylinders having diameters on the order of approximately1.75 millimeters at the first end 160 of the intermediate link 128, andthe third groove 178 is configured as a segment of a cylinder having adiameter on the order of approximately 2.50 millimeters at the first end160 of the intermediate link 128. The first, second and third grooves174, 176, 178 are each configured to receive and partially surround anyof a variety of tools or instruments (e.g., ablation tools) which maypass from the first end 24 of the multi-linked device 10 to the secondend 26 of the multi-linked device 10.

The intermediate link 128 also defines a passage 180 extending from thefirst end 160 to the second end 162 along the longitudinal axis 164 asshown in FIG. 8B. The passage 180 is of a size sufficient to allow thefirst mechanism 12 to pass therethrough. According to variousembodiments, the passage 180 is generally configured as a complex shapethat comprises a combination of a segmented hemisphere 182 that extendsfrom the first end 160 toward the second end 162, a first segmented cone184 that extends from the segmented hemisphere 182 toward the second end162, a cylinder 186 that extends from the first segmented cone 184toward the second end 162, and a second segmented cone 188 that extendsfrom the cylinder 186 to the second end 162 of the intermediate link128. According to various embodiments, the segmented hemisphere 182represents a portion of a sphere having a diameter on the order ofapproximately 9.65 millimeters, the first segmented cone 184 is taperedat an angle on the order of approximately 15° relative to thelongitudinal axis 164, the cylinder 186 has a diameter on the order ofapproximately 5.50 millimeters, and the second segmented cone 188 istapered at an angle on the order of approximately 15° relative to thelongitudinal axis 164. The segmented hemisphere 182 of the passage 180is configured to receive the second end 132 of the first link 124 whenthe first link 124 is coupled to the intermediate link 128. Similarly,for a given intermediate link 128, the segmented hemisphere 182 of thepassage 180 is configured to receive the second end 162 of anotherintermediate link 128 when the other intermediate link 128 is coupled tothe given intermediate link 128.

The intermediate link 128 also defines a first through-hole 190, asecond through-hole 192, and a third through-hole 194. (See FIG. 8C).The first through-hole 190 is substantially parallel to the longitudinalaxis 164, extends from the first portion 166 toward the second end 162,and is positioned between the passage 180 and the first surface 170. Thesecond through-hole 192 is substantially parallel to the longitudinalaxis 164, extends from the first portion 166 to the second end 162, andis positioned between the passage 180 and the first surface 170. Thethird through-hole 194 is substantially parallel to the longitudinalaxis 164, extends from the first portion 166 to the second end 162, andis positioned between the passage 180 and the first surface 170. Thefirst, second and third through-holes 190, 192, 194 are generallycylindrically shaped. According to various embodiments, thethrough-holes 190, 192, 194 are evenly spaced from one another. The sizeof each of the through-holes 190, 192, 194 may be identical to oneanother or may be different from one another. For example, according tovarious embodiments, the respective diameters associated with thethrough-holes 190, 192, 194 may each be on the order of approximately1.25 millimeters. The first through-hole 190 is configured to receiveand surround the first cable 16. The second through-hole 192 isconfigured to receive and surround the second cable 18. The thirdthrough-hole 194 is configured to receive and surround the third cable20. The first, second and third through-holes 190, 192, 194 may serve asguidepaths for movement of the first, second and third cables 16, 18,20.

As shown in FIG. 8C, the intermediate link 128 also defines first,second and third indents 196, 198, 200 at the second end 162 thereofresulting, in part, from the combination of the taper associated withthe second portion 168 and the configuration and orientation of thefirst, second, and third grooves 174, 176, 178. The first, second andthird indents 196, 198, 200 may be evenly spaced about the second end162 of the intermediate link 128 as shown in FIG. 8C. The first, secondand third indents 196, 198, 200 may serve to reduce the pinching orbinding of various tools or instruments (e.g., ablation tools) when oneintermediate link 128 of the second mechanism 14 is moved relative toanother intermediate link 128 coupled thereto.

The intermediate link 128 also defines fourth, fifth and sixth indents202, 204, 206 at the second end 162 thereof resulting from thecombination of the taper associated with the second portion 168 and theconfiguration and orientation of the first, second, and thirdthrough-holes 190, 192, 194. The fourth, fifth and sixth indents 202,204, 206 may be evenly spaced about the second end 162 of theintermediate link 128, and may be evenly spaced from the first, secondand third indents 196, 198, 200 as shown in FIG. 8C. The fourth, fifthand sixth indents 202, 204, 206 may serve to reduce the pinching orbinding of the first, second and third cables 16, 18, 20 when oneintermediate link 128 of the second mechanism 14 is moved relative toanother intermediate link 128 coupled thereto.

According to various embodiments, an intermediate link 128 may alsodefine an opening (not shown) that extends from the second surface 172or from one of the grooves 174, 176, 178 to the first surface 170 of theintermediate link 128. The intermediate link 128 may have any number ofsuch openings, and any number of the intermediate links 128 may havesuch openings. The opening may be utilized as an exit point for a toolor instrument which may pass from the first end 24 of the multi-linkeddevice 10 toward the second end 26 of the multi-linked device 10. Forsuch embodiments, the respective intermediate link 128 may be positionedproximate the second link 126 of the second mechanism 14. The openingmay be oriented at any angle relative to the longitudinal axis 134 ofthe intermediate link 128. When the first mechanism 12 is removed fromthe second mechanism 14, and a relatively large tool or instrument isadvanced from the first end 120 of the second mechanism 14 to the secondend 122 of the second mechanism 14, sufficient room may not exist for asecond tool or instrument (e.g., fiber optic cable) to pass through thesecond end 122 of the second mechanism 14. For such instances, thesecond tool or instrument may exit through an opening of one of theintermediate links 128.

With the above described structure, the first link 124 may be coupled tothe intermediate link 128 by seating the second end 132 of the firstlink 124 in the segmented hemisphere 182 of the passage 180 of theintermediate link 128. As the convex configuration of the second end 132of the first link 124 generally corresponds with the concaveconfiguration of the segmented hemisphere 182 of the passage 180 of theintermediate link 128, the first link 124 may be coupled to theintermediate link 128 such that the longitudinal axis 134, the first,second and third grooves 142, 144, 146, and the first, second and thirdthrough-holes 154, 156, 158 of the first link 124 are respectivelyaligned with the longitudinal axis 164, the first, second and thirdgrooves 174, 176, 178, and the first, second and third through-holes190, 192, 194 of the intermediate link 128. The intermediate link 128may be moved relative to the first link 124 such that the longitudinalaxis 164 of the intermediate link 128 is not aligned with thelongitudinal axis 134 of the first link 124. According to variousembodiments, the configuration of the first link 124 and theintermediate link 128 allows for the intermediate link 128 to be movedrelative to the first link 124 coupled thereto such that thelongitudinal axis 134 of the first link 124 and the longitudinal axis164 of the intermediate link 128 are up to approximately 10° out ofalignment with one another. Similarly, one intermediate link 128 may becoupled to another intermediate link 128, and so on, by seating thesecond end 162 of one intermediate link 128 in the segmented hemisphere182 of the passage 180 of another intermediate link 128. As the convexconfiguration of the second end 162 of the intermediate link 128generally corresponds with the concave configuration of the segmentedhemisphere 182 of the passage 180 of the intermediate link 128, theintermediate links 128 may be coupled such that the respectivelongitudinal axes 164, the respective first, second and third grooves174, 176, 178, and the respective first, second and third through-holes190, 192, 194 of the intermediate links 128 are aligned. The coupledintermediate links 128 may be moved relative to one another such thatthe respective longitudinal axes 164 of the coupled intermediate links128 are not aligned. According to various embodiments, the configurationof the coupled intermediate links 128 allows for one intermediate link128 to be moved relative to another intermediate link 128 coupledthereto such that the respective longitudinal axes 164 are up toapproximately 10° out of alignment with one another.

FIGS. 9A-9D illustrate various embodiments of the second link 126 (outerdistal link) of the second mechanism 14. The second link 126 includes afirst end 208 and a second end 210, and defines a longitudinal axis 212that passes through the center of the first end 208 and the center ofthe second end 210 as shown in FIG. 9C. The second link 126 may befabricated from any suitable material. According to various embodiments,the second link 126 is fabricated from a thermoplastic material such as,for example, Delrin®.

The second link 126 comprises a first portion 214 and a second portion216. The first portion 214 may be considered the proximal portion andthe second portion 216 may be considered the distal portion. The firstportion 214 may be fabricated integral with the second portion 216. Thefirst portion 214 has a generally cylindrical shaped exterior, andextends from the first end 208 of the second link 126 toward the secondend 210 of the second link 126. According to various embodiments, thediameter of the first portion 214 is on the order of approximately 4.80millimeters.

According to various embodiments, the second portion 216 has a generallycylindrically shaped exterior where it contacts the first portion 214,and tapers toward the second end 210 of the second link 126. Theexterior of the second portion 216 is configured in the form of agenerally segmented cone. According to various embodiments, the exteriorof the second portion 216 tapers from the first portion 214 to thesecond end 210 of the second link 126 at an angle on the order ofapproximately 20° relative to the exterior of the first portion 214. Thelength of the second link 126 may be on the order of approximately 15millimeters. However, one skilled in the art will appreciate that thelength of the second link 126 can vary based on the application.

The second link 126 also comprises a first surface 218 that extends fromthe first end 208 of the second link 126 to the second end 210 of thesecond link 126, and a second surface 220 that extends from the firstend 208 of the second link 126 toward the second end 210 of the secondlink 126. The first surface 218 may be considered the outer surface ofthe second link 126, and the second surface 220 may be considered theinner surface of the second link 126.

The second link 126 also defines a first port 222, a second port 224,and a third port 226. (See FIG. 9B). The first port 222 extends from thesecond surface 220 to the first surface 218 and is substantiallyparallel to the longitudinal axis 212. The second port 224 extends fromthe second surface 220 to the first surface 218 and is substantiallyparallel to the longitudinal axis 212. The third port 226 extends fromthe second surface 220 to the first surface 218 and is substantiallyparallel to the longitudinal axis 212. The first, second and third ports222, 224, 226 may be cylindrical shaped and may be evenly spaced aboutthe longitudinal axis 212 of the second link 126 as shown in FIG. 9D.The size of each of the ports 222, 224, 226 may identical to one anotheror may be different from one another. For example, according to variousembodiments, the first and second ports 222, 224 are configured ascylinders having diameters on the order of approximately 1.50millimeters, and the third port 226 is configured as a cylinder having adiameter on the order of approximately 2.50 millimeters. The first,second and third ports 222, 224, 226 are each configured to receive andsurround any of a variety of tools or instruments (e.g., ablation tools)which may pass from the first end 24 of the multi-linked device 10 tothe second end 26 of the multi-linked device 10.

The second link 126 also defines a first through-hole 228, a secondthrough-hole 230, and a third through-hole 232. (See FIG. 9B). The firstthrough-hole 228 extends from the second surface 220 to the firstsurface 218 and is substantially parallel to the longitudinal axis 212.The second through-hole 230 extends from the second surface 220 to thefirst surface 218 and is substantially parallel to the longitudinal axis212. The third through-hole 232 extends from the second surface 220 tothe first surface 218 and is substantially parallel to the longitudinalaxis 212. The first, second and third through-holes 228, 230, 232 aregenerally cylindrically shaped. According to various embodiments, thethrough-holes 228, 230, 232 are evenly spaced from one another as shownin FIG. 9D. The size of each of the through-holes 228, 230, 232 may beidentical to one another or may be different from one another. Forexample, according to various embodiments, the respective diametersassociated with the through-holes 228, 230, 232 may each be on the orderof approximately 1.25 millimeters. The first through-hole 228 isconfigured to receive and surround the first cable 16. The secondthrough-hole 230 is configured to receive and surround the second cable18. The third through-hole 232 is configured to receive and surround thethird cable 20.

The second link 126 also defines a recess 234 that extends from thefirst end 208 toward the second end 210 along the longitudinal axis 212as shown in FIG. 9C. According to various embodiments, the recess 234 isgenerally configured as a complex shape that comprises a combination ofa first segmented hemisphere 236 that extends from the first end 208toward the second end 210, and a second segmented hemisphere 238 thatextends from the first segmented hemisphere 236 toward the second end210 of the second link 126. According to various embodiments, the firstsegmented hemisphere 236 represents a portion of a sphere having adiameter on the order of approximately 9.50 millimeters, and secondsegmented hemisphere 238 represents a portion of a sphere having adiameter on the order of approximately 7.0 millimeters. The firstsegmented hemisphere 236 of the recess 234 is configured to receive thesecond end 162 of an intermediate link 128 when the intermediate link128 is coupled to the second link 126.

With the above described structure, an intermediate link 128 may becoupled to the second link 126 by seating the second end 162 of theintermediate link 128 in the first segmented hemisphere 236 of therecess 234 of the second link 126. As the convex configuration of thesecond end 162 of the intermediate link 128 generally corresponds withthe concave configuration of the first segmented hemisphere 236 of therecess 234 of the second link 126, the intermediate link 128 may becoupled to the second link 126 such that the longitudinal axis 164, thefirst, second and third grooves 174, 176, 178, and the first, second andthird through-holes 190, 192, 194 of the intermediate link 128 arerespectively aligned with the longitudinal axis 212, the first, secondand third ports 222, 224, 226, and the first, second and thirdthrough-holes 228, 230, 232 of the second link 126. The second link 126may be moved relative to the intermediate link 128 coupled thereto suchthat the respective longitudinal axes 164, 212 are not aligned.According to various embodiments, the configuration of the second link126 allows for an intermediate link 128 coupled thereto to be movedrelative to the second link 126 such that the respective longitudinalaxes 164, 212 are up to approximately 10° out of alignment with oneanother.

When the first mechanism 12 is inserted into the second mechanism 14,the first second and third grooves 70, 72, 74 of the intermediate links32 of the first mechanism 12 may be substantially aligned with thefirst, second and third grooves 174, 176, 178 of the intermediate links128 of the second mechanism 14, and the first, second and third grooves98, 100, 102 of the second link 30 of the first mechanism 12 may besubstantially aligned with the first, second and third ports 222, 224,226 of the second link 126 of the second mechanism 14. The combinationof the first grooves 70 of the intermediate links 32 of the firstmechanism 12 aligned with the first grooves 174 of the intermediatelinks 128 of the second mechanism 14 allows the respective first grooves70, 174 to collectively serve as a first working port that issubstantially aligned with the first port 222 of the second link 126 ofthe second mechanism 14. As used herein, the term “working port” means apassageway through which a device (e.g., a camera, a fiber optic, anablation tool, a surgical instrument, etc.) can pass. The first groove70 may be considered the inner portion of the first working port and thefirst groove 174 may be considered the outer portion of the firstworking port.

Similarly, the combination of the second grooves 72 of the intermediatelinks 32 of the first mechanism 12 aligned with the second grooves 176of the intermediate links 128 of the second mechanism 14 allows therespective second grooves 72, 176 to collectively serve as a secondworking port that is substantially aligned with the second port 224 ofthe second link 126 of the second mechanism 14, and the combination ofthe third grooves 74 of the intermediate links 32 of the first mechanism12 aligned with the third grooves 178 of the intermediate links 128 ofthe second mechanism 14 allows the respective third grooves 74, 178 tocollectively serve as a third working port that is substantially alignedwith the third port 226 of the second link 126 of the second mechanism14. The second groove 72 may be considered the inner portion of thesecond working port and the second groove 176 may be considered theouter portion of the second working port. The third groove 74 may beconsidered the inner portion of the third working port and the thirdgroove 178 may be considered the outer portion of the third workingport. The first, second and third working ports may be utilized to passvarious tools or instruments (e.g., ablation tools) from the first end24 of the multi-linked device 10 to the second end 26 of themulti-linked device 10. For the exemplary sizes described hereinabove,the third working port is larger than the first and second workingports. Accordingly, the third working port may be utilized to carry aparticular tool or instrument that is too large to be carried by thefirst or second working ports.

When the respective grooves 70, 72, 74, 174, 176, 178 of the respectiveintermediate links 32, 128 are aligned and collectively surround thevarious tools and instruments, the combination of the grooves 70, 72,74, 174, 176, 178 and the tools and instruments may serve to limit orprevent the rotation of the first mechanism 12 relative to the secondmechanism 14.

As the diameter of the passage 180 of the intermediate link 128 of thesecond mechanism 14 is larger than the diameter of any portion of thefirst mechanism 12, a three-dimensional space 240 exists between thefirst mechanism 12 and the second mechanism 14 when the first mechanism12 is received by the second mechanism 14 (See FIG. 1B). According tovarious embodiments, the space 240 may be utilized to carry wiring,tools, instruments, etc. from the first end 24 of the multi-linkeddevice 10 toward the second end 26 of the multi-linked device 10.

The first, second and third cables 16, 18, 20 may be fabricated from anysuitable material. For example, according to various embodiments, thecables 16, 18, 20 may be fabricated from a polyethylene fiber cable suchas, for example, Spectra®. The cables 16, 18, 20 may be utilized tocontrol the movement of the multi-linked device 10. For example, byapplying a substantially equal tension to each of the cables 16, 18, 20,the first mechanism 12 and/or second mechanism 14 may be steered in adirection such that the respective longitudinal axes 38, 62, 90, 134,164, 212 of each of the links 28, 30, 32, 124, 126, 128 are all aligned.By applying a different tension to one or more of the cables 16, 18, 20,the first mechanism 12 and/or the second mechanism 14 may be steered ina direction such that the respective longitudinal axes 38, 62, 90, 134,164, 212 of each of the links 28, 30, 32, 124, 126, 128 are not allaligned. The cables 16, 18, 20 may also be utilized to control therelative state of the second mechanism 14. For example, when a uniformtension is applied to the cables 16, 18, 20, the second mechanism 14 isplaced in a “rigid” state, and when a tension is removed from the cables16, 18, 20, the second mechanism 14 is placed in a “limp” state.According to various embodiments, the cables 16, 18, 20 may be attachedat the first end 130 of the first link 124 of the second mechanism 14 torespective pullies (not shown) by, for example, respective stopperknots. The cables 16, 18, 20 may be attached to the second end 132 ofthe second link 126 of the second mechanism 14 by, for example,respective stopper knots. One skilled in the art will appreciate that,according to other embodiments, the “rigid” and “limp” states may beachieved by subjecting the first and/or second mechanisms 12, 14 to atwisting force, or by any other manner known in the art.

The fourth cable 22 may be fabricated from any suitable material. Forexample, according to various embodiments, the cable 22 may befabricated from a polyethylene fiber cable such as, for example,Spectra®. The fourth cable 22 may be utilized to control the relativestate of the first mechanism 12. For example, when the fourth cable 22is drawn tight, the first mechanism 12 is placed in a “rigid” state,whereas when the fourth cable 22 is let loose, the first mechanism 12 isplaced in a “limp” state. According to various embodiments, the fourthcable 22 may be attached at the first end 34 of the first link 28 of thefirst mechanism 12 to a pully (not shown) by, for example, a stopperknot. The fourth cable 22 may be attached to the second end 88 of thesecond link 30 of the first mechanism 12 by, for example, a stopperknot.

FIG. 10 illustrates various embodiments of a motion sequence of thesteerable multi-linked device 10. At the start of the sequence, thesecond mechanism 14 surrounds the first mechanism 12 as shown in step“a” of FIG. 10, the longitudinal axes 38, 62, 90 of the links 28, 30, 32of the first mechanism 12 are substantially aligned with the respectivelongitudinal axes 134, 164, 212 of the links 124, 126, 128 of the secondmechanism, and the second end 26 of the first mechanism 12 is atsubstantially the same position as the second end 122 of the secondmechanism 14. The fourth cable is pulled tight, thereby placing thefirst mechanism 12 in the rigid mode. The cables 16, 18, 20 are notpulled tight, thereby placing the second mechanism 14 in the limp mode.

The second mechanism 14 is then advanced so that its second link 126 ispositioned approximately one link ahead of the second end 24 of thefirst mechanism 12 as shown in step “b” of FIG. 10. The cables 16, 18,20 may be utilized to orient the second link 126 to a particularorientation, where the longitudinal axis 134 of the first link 124 is nolonger aligned with the longitudinal axes 164 of the intermediate links128 of the second mechanism 14 or the longitudinal axis 90 of the secondlink 30 of the first mechanism 12. After the second link 126 is in thedesired position and orientation, the cables 16, 18, 20 are pulled withidentical force in order to place the second mechanism 14 in the rigidmode, thereby preserving the position and orientation of the secondmechanism 14.

The pulling force of the fourth cable 22 is then released to place thefirst mechanism 12 the limp mode. After the first mechanism 12 is placedin the limp mode, the first mechanism 12 is advanced so that its secondlink 30 is at substantially the same position as the second end 122 ofthe second mechanism 14 as shown in step “c” of FIG. 10. After thesecond link 30 of the first mechanism 12 is in the desired position andorientation, the fourth cable 22 is pulled tight to place the firstmechanism 12 back in the rigid mode, thereby preserving the position andorientation of the first mechanism 12.

The pulling forces of the cables 16, 18, 20 are then released to placethe second mechanism 14 back in the limp mode. After the secondmechanism 14 is placed back in the limp mode, the second mechanism 14 isadvanced so that its second link 126 is once again positionedapproximately one link ahead of the second end 26 of the first mechanism12 as shown in step “d” of FIG. 10. After the second link 126 is in thedesired position and orientation, the cables 16, 18, 20 are pulled withidentical force in order to place the second mechanism 14 in the rigidmode, thereby preserving the position and orientation of the secondmechanism 14.

The pulling force of the fourth cable 22 is then released to place thefirst mechanism 12 back in the limp mode. After the first mechanism 12is placed back in the limp mode, the first mechanism 12 is advanced sothat its second link 30 is once again at substantially the same positionas the second end 122 of the second mechanism 14 as shown in step “e” ofFIG. 10. After the second link 30 of the first mechanism 12 is in thedesired position and orientation, the fourth cable 22 is pulled tight toplace the first mechanism 12 back in the rigid mode, thereby preservingthe position and orientation of the first mechanism 12. The generalmotion sequence described hereinabove, may be repeated any number oftimes, and the second link 126 of the second mechanism 14 may beadvancing in any direction and orientation. One skilled in the art willappreciate that any number of motion sequences may be utilized with themulti-linked device 10. For example, according to various embodiments,the second mechanism 14 may advance any number of links ahead of thefirst mechanism 12.

The exemplary sizes described hereinabove are generally relative to eachother, and one skilled in the art will appreciate that the multi-linkeddevice 10 can be scaled up or scaled down. For example, although thediameter at the largest portion of the intermediate link 128 of themulti-linked device 10 is on the order of approximately 9.65 millimetersfor the embodiments described hereinabove, one skilled in the art willappreciate that, for other embodiments, the intermediate link 128 can bescaled down such that the diameter at the largest portion of theintermediate link 128 of the multi-linked device 10 is on the order ofapproximately 1.0 millimeter. For such embodiments, each of the othercomponents of the multi-linked device 10 would also be proportionallyscaled down.

The combination of the unique configuration of the respective links 28,30, 32 which comprise the first mechanism 12 and the uniqueconfiguration of the respective links 124, 126, 128 which comprise thesecond mechanism 14 provides the multi-linked device 10 with the abilityto traverse a path defined by the circumference of a circle having arelatively small radius. For example, for the exemplary sizes describedhereinabove, the multi-linked device 10 can traverse a path defined bythe circumference of a circle having a radius on the order ofapproximately 40 millimeters. An example of the multi-linked device 10navigating such tight curvatures is shown in FIG. 11. For embodiments,where the largest portion of the intermediate link 128 of themulti-linked device 10 is on the order of approximately 1.0 millimeter,the multi-linked device 10 can traverse a path defined by thecircumference of a circle having a radius significantly smaller than 45millimeters (e.g., on the order of approximately 4.0 millimeters).Stated differently, the multi-linked device 10 can traverse a pathdefined by a circumference of a circle having a radius which isapproximately four times the outer diameter of the device 10. Oneskilled in the art will appreciate that the ability to navigate suchtight curvatures makes the multi-linked device 10 suitable for use in anumber of different minimally invasive procedures, both in luminalspaces and in intracavity spaces.

While several embodiments of the invention have been described herein byway of example, those skilled in the art will appreciate that variousmodifications, alterations, and adaptions to the described embodimentsmay be realized without departing from the spirit and scope of theinvention defined by the appended claims. For example, one skilled inthe art will appreciate that the multi-linked device 10 may comprise anynumber any number of working ports. Also, the first mechanism 12 mayfurther comprise through-holes and cables in lieu of the fourth cable 22such that the first mechanism 12 is steerable.

1. (canceled)
 2. A method of advancing a steerable, multi-linked device,the method comprising: positioning an outer multi-linked mechanism sothat it surrounds an inner multi-linked mechanism, wherein the outermulti-linked mechanism comprises a plurality of links, wherein the innermulti-linked mechanism comprises a plurality of links, wherein alongitudinal axis of the links of the outer multi-linked mechanismsubstantially aligns with a longitudinal axis of the links of the innermulti-linked mechanism; applying tension on a first cable to place theinner multi-linked mechanism in a rigid mode; advancing the outermulti-linked mechanism such that a distal link of the outer multi-linkedmechanism is positioned approximately one link ahead of a distal end ofthe inner multi-linked mechanism; applying tension to one or more secondcables to place the outer multi-linked mechanism in the rigid mode;releasing the tension on the first cable to place the inner multi-linkedmechanism in a limp mode; and advancing the inner multi-linked mechanismso that a distal link of the inner multi-linked mechanism is positionedat approximately a same position of the distal link of the outermulti-linked mechanism.
 3. The method of claim 2, further comprisingorienting a position of the distal link of the outer multi-linkedmechanism using at least one of the second cables such that alongitudinal axis of a first link of the outer multi-linked mechanism isnot aligned with one or more other links of the outer multi-linkedmechanism.
 4. The method of claim 2, wherein the tension placed on thefirst cable is substantially the same as the tension applied to the oneor more second cables.
 5. The method of claim 2, further comprisingorienting a position of the distal link of the inner multi-linkedmechanism using the first cable while the inner multi-linked mechanismis operating in the limp mode.
 6. The method of claim 5, furthercomprising: applying tension on the first cable to place the innermulti-linked mechanism in the rigid mode and to preserve the orientationof the inner multi-linked mechanism.
 7. The method of claim 2, furthercomprising: after advancing the inner multi-linked mechanism so that adistal link of the inner multi-linked mechanism is positioned atapproximately a same position of the distal link of the outermulti-linked mechanism: applying tension on the first cable to place theinner multi-linked mechanism in the rigid mode, releasing the tension onone or more of the second cables to place the outer multi-linkedmechanism in the limp mode, and advancing the outer multi-linkedmechanism.
 8. The method of claim 7, wherein advancing the outermulti-linked mechanism comprises: advancing the outer multi-linkedmechanism so that the distal link of the outer multi-linked mechanism ispositioned approximately one link ahead of the distal link of the innermulti-linked mechanism.
 9. The method of claim 7, further comprisingorienting a position of the distal link of the outer multi-linkedmechanism using at least one of the second cables.
 10. The method ofclaim 9, further comprising applying tension to one or more of thesecond cables to place the outer multi-linked mechanism in the rigidmode to preserve the orientation of the outer multi-linked device. 11.The method of claim 7, further comprising: applying tension to one ormore of the second cables to place the outer multi-linked mechanism inthe rigid mode.